So you can edit the indicator and change the time manually, seems to have fixed it, could you confirm? Chart below is GBPJPY, does it match up with yours?
Don’t just do things by trial and error. Look at what your Broker’s time-zone or server time is, and then adjust the open and close times accordingly.
As an extra aid, look at MyFXBook’s dashboard and see the open/close times for the different sessions and compare the time difference to your broker’s server time and then set the correct times for the indicator.
EDIT: PS! Just because you live in the UK does not mean that your Broker uses the UK’s time zone. ALWAYS check which time-zone your broker uses and what Daylight Savings times are used. For example, they could use UTC+2 and then use USA DST instead of European DST. Do the research. Don’t just use trial-and-error.